Compaction, Geo-grid , and proper drainage, important factors that’s makes a retaining wall last forever. IF ANY OF THE THREE IS NOT DONE CORRECT YOUR WALL WILL COME DOWN !!!!
So What is Compaction?
Compaction is the process of rearranging soils to consolidate the space occupied by the soil particles while forcing out excess air and water.
Why is it important?
Properly compacted soils help to strengthen the internal strength of the soil mass by aligning the soil particles together and increasing the coefficient of friction when a load is applied to the soil, and reducing undesirable settlement. Most compaction must meet the the so called standard proctor test of 90-95%.
So what type of equipment do you need to pass this test?
1. Vibratory plate: Vibratory machines send waves of motion through the soil to re position and consolidate the soil particles. Vibratory machines work well in non cohesive soils; soils comprised of at least 50 percent sand or gravel. Walk behind one’s can weigh from 250 pounds and up..
2. Jumping Jack: (check out the video) This piece of equipment is not for the weak . It will give your arms a true workout. This is use best for cohesive soil such as clay. As the video shows above it jumps up and down about 700 times a minute and weighs about 150 pounds. We always flip a coin on who is going to use it for the day…lol
3.Sheep Foot: This beast can weigh up to 5000 lbs. (check out the video)This machine is also use for cohesive soil such as clay. You normally can compact dirt in 8 inch lifts. When using this machine is best to stay at least 2-3 feet from the wall the vibration can push the retaining wall out some.
4. Equipment: Sometimes the sheer weight of the equipment will compact the soil. We use the excavator along with a sheep foot roller (check out the video)to get to our 95%: This excavator weighs close to 19,000 pounds.
This is how it looks after the equipment went back and forth. We back fill and compact over 1000 yards. For every 13 yards of fill dirt it compacts down to 10 yards !!!!!!!!!!!!!!!!
Who is All Access?
From concrete to retaining walls, modern landscape to pavers. All Access is one of the Bay Area and Northern California’s most well–respected hardscape and landscape contractors. Contact us for your next project by making an appointment online or the old fashion way 510-701-4400
4 Comments
Joe, Blog was well written. Have you ever thought of using a 3′ column of clean stone directly behind the wall? It will prevent using any compaction equipment within the 3′ zone behind the wall and provide labor savings. Clean #57 stone needs zero compaction since it it fully consolidated upon pouring it behind the wall.
Never thought of it,but I will look into it. Is that the same rock they use for Permeable pavers? Any thing to save money and time
Yes, they may call it something different out by you. It is a clean 3/4″ – 1″ stone.
Do you have any specs for it.? I know what you are talking about . I always said drain rock works best, but I dont have any facts backing it up!!! I know you guys are on the east coast Look up Ryan’s landscaping out of PA ,Davison 4 season out of Ohio…